Some corrections of my precedent assertions. Indeed the rope can be curved, the losses shown in 

http://www.sswhite.net/unidirection_metric.htm for curved shaft being low. So a big pilot-kite sustaining not perfectly lifting rotors would be something possible until some value. Other correction for my precedent message: to be like the example of flexible shaft the motor is settled in a end of shaft, but for SuperTurbine(R) rotors work as motors and are along the rope-shaft. So perhaps the diameter is deduced by taking account of the length between only two rotors instead the whole rope. Of course we suppose rotors are well synchronized. In this scenario the diameter of the rope is far lower.
The better for you DougS would be asking Pr. Dave Lang to make a simulation of rotating tether, and also of autogyro-rotor for lift and torque.
But providing some measures on your flexible Serpentine video would allow a beginning.

Another problem is the stability of AoA of lifting rotors expected to be perpendicular in the rope.But the rope can be tilted at different angles, excepted in case of use of pilot-kite for stabilisation (not only for lift).

 

PierreB

Yeah Pierre that is why the ST patents show a stack of gyrocopters.

Thanks for your opinion, Dave S.  Yes the CEC-funded effort was a tip-of-the-iceberg confirmation of the basic power capabilities of the configuration.  Yes I would like to explore the AWE aspects more thoroughly.  We do agree on that.  Talking about AWE on the web does not seem to give any results.  What do you think?

The CEC study validates the feature of several rotors on the same shaft, in any directions, both as ground-based turbine and as AWES. But Serpentine as AWES has some supplement questions to validate, and in first the flexible very long shaft. The video shows it looks possible, and it is possible each rotor works as a motor turning its part of shaft. Some tests and/or simulations are needed to see different aspects: lift of rotors, tension and angle of curve of shaft, resilient materials for shaft allowing allowing temporary differential rotation according to each respective rotor...

 

PierreB

DaveS,

 

No relevant.

 

PierreB

Pierre I agree
The world at large is not all that impressed with patents until they see working examples.  If the performance is good, people are impressed.  If not, then not.  Take FloDesign turbine funded by Kleiner Perkins.  They had patents, they had at least one "Professor Crackpot" insisting that such a high-solidity contraption was superior to prior-art low-solidity turbines.  They would not listen to my warnings.  I told them it was symptomatic of the Professor Crackpot syndrome, I told them it was a "Professor-Crackpot-on-steroids" turbine that merely combined several known blind-alleys in turbine design into a single terrible result.  They did not listen to me (or maybe they eventualy did) and put millions and millions of dollars into creating a small number(one?)  of maybe ~10 kW prototypes(?).  The result was probably the most expensive turbine at that size ever.  I've heard of one about 80 miles from here.  The performance must have been lackluster.  How do you know?  We don't hear about it anymore. (They quietly go away...)  The problem is they found a way to use many times the material to get maybe a teeny bit more power, or, more likely, slightly less power, than previous, comparably-sized turbine designs.  The difference between SuperTurbine(R) and other "new" turbine styles is ST really IS a new idea, whereas most of the rest are rehashed ideas from yesteryear.  ST is a very versatile tool for the exchange of kinetic energy from an open flow.  The variety of possible configurations and implementations offer an overwhelming number of promising avenues for exploration.



The people administering the grants told me most awardees never finish their projects.

So how does your pet moth stack up by your own stated standards?

Daniel J. Hunter had entered another idea that I missed until today: 

Old and new: The harvesting of atmospheric electricity for practical use seems to be a theme that cycles into view again and again. The topic is not just about grabbing lightning.  Notes and discussion might flow from this topic thread. Also harvesting some unwanted atmospheric electricity may be seen as part of the AWES environment, as has been mentioned in forum; off-putting unwanted charges is part of the game. 

Hey Joe:
Interesting twist.  That's Professor Crackpot on Steroids again: I remember a similar idea "floating" around a few years ago for a new world airborne transportation system.  It was something similar by varying the pressure in a blimp or a plane or something, coasting up and down at an angle due to positive or negative buoyancy, the airplane engine was suddenly "obsolete", because their version of perpetual motion used air pressure and altitude instead of, say, magnets or just gravity on solid objects.  I think when you have to compress air to go down, it takes the same amount of energy to compress the air as what you get back.  Ya know, conservation of energy?  Just sayin'
I had a conversation today about Brown's gas.  A neighbor of mine knew Dr. Brown.  Hung out with him. He was telling me how Dr. Brown split water and get back 10 times as much energy recombining the oxygen and hydrogen.  Oh, and the "flame" neaturalizes nuclear waste!  A chemical process that solves nuclear problems.  This is when I know the professor is in the house.  His tracks are all around.  More energy out than in, forever, just... no... working model.  Or you can't see one because it's secret.  But hey, before you think too hard about that concept of neatly solving the intractable issue of perpetual motion, gosh darn doncha know we need to move on to the next magic thing it does, see, free energy forever is not enough.  We have to have a chemical reaction that solves nuclear waste problems too.  Now is that enough for you?  My neighbor told me the world didn't understand, because Dr. Brown's method doesn't follow standard engineering principles. I told him it's not engineering principles so much as Mother nature - she never lies.  Either you can whoop her or you can't.  Anyway, regarding the flame neutralizing nuclear waste, I told him I was interested in trying a new kind of welder that uses electricity to split water and immediately recombines the gasses in a flame that welds, if I have the story right.  "Dr. Brown invented that!" he told me, "Back in the 1940's" or something like that.  Well maybe if I get one it will not only gas weld off household current but lower my electric bill by spinning the meter backwards! :)

Maboomba! 

Hey Joe I'm not catching what the LE abbreviation is for, but I'd suggest anyone contemplating this idea of using kites to lift another larger kite that is momentarily pulling down(?), go out to the windfarms near Palm Springs on a windy day, and bring whatever kite you think you might use, and see how it flies when the winds hit 70 mph at hub height.
The second (still handheld at that time) SuperTurbine(R) I ever built almost ripped apart while burning out its light-bulb load in about 1 second when I first tried testing in an actual windfarm environment.  I guess I'm lucky they didn't find me laying there a few days later.  Wind!  Who knew?  Park your car headed INTO the wind, lest you lose a door.

Hey Roddy, if someone showed you a (real) wind turbine and all the blades could do was wiggle (loose rotor?), you would say "why do you stop at a mere wiggle?  Why not let that thing spin? You'll never generate any power with a little wiggle!"  You have rendered a nice SuperTurbine(R) if you would let it spin.  Or stay wiggling, and talk about "block&tackle"(?).  I'm a little puzzled: Rotation was discovered in wind energy 3000 years ago, and has proven to be fruitful since then.  The wiggle thing has always failed.  Last time was 1000 years ago in China.  Why do would-be, wannabe wind energy "inventors" want to go back to some ancient point, thousands of years ago, before wind energy was viable in any sense, and beat their head against the wall with more unworkable designs?  Is  the theory that if one wiggling kite sucks, a whole stack of them will really suck hard? :)

Fine Dave S., you are a genius and have all the answers as usual.  What you write, as always, makes no sense.  Sure, go ahead and use wiggle-power.  Nobody is stopping you.  Of course I know what a leading edge is, and you know that, so implying that I don't is just your way of expressing your own impossible-to-deal-with-in-a-rational-way-ness.   You make yourself look bad, not me.  And you are not educating me in any way, let alone in aerospace.  I just did not know what Joe meant by LE.  People tend to use abbreviations while sometimes forgetting that not everyone knows what they mean by every abbreviation, every time.

Are you talking about that giant rectangular kite in Life Magazine back in the 1980's that killed a guy whose ankle got caught in a line?  Was that a "Budweiser" (logo) kite?     ("Osborne's world-record largest kite killed Eideken")  I used to imagine what went through that guy's mind as he was being hoisted up 100 feet by one ankle: "Why did I do this?!?!?!?! Uh-Oh, this could turn out real bad - Help Mr. Wizard!"
Unfortunately he never heard "Drizzle Droozle Drazzle Drone, Time for This One to Come Home"

Thanks, Doug. 

Thanks Joe
Sounds obvious in retrospect, but hard to say.  If I were reading about airplane design, in a discussion of the wing, I would know what was meant.  People are unlikely to look up every abbreviation in a glossary, given the time it takes and the fact that nothing here has much meaning or shows any progress or promise anyway.
I'd recommend people just type out the complete words for anything where there's a question of whether most readers will understand the meaning either from our in-house common usage (like "AWE") or the context.
I could imagine LE could mean something like "lift envelope" or some weird thing.  Dave S. did spell out RAD meaning - geez I forgot already - Rock Against Drugs?  Nah.  OK I remember:Rapid Deployment of AWE, which is an acronym of an acronym, also a meaningless statement since AWE is not being rapidly deployed anywhere since nobody has any decent models working and not only that, most teams are pursuing methods that do not, in my mind anyway, even look promising.  This whole kite-reeling thing is seriously misguided as far as I can see.  Kite-reeling is just a way of saying "I can't think my way out of a paper bag".   Kites pull, right?  Yeah.  They pull.  Whoopee-doo.  Can we go over that again?  Kites pull.  Oh yeah, then you have to reel it back in.  Here's a slogan for the reel-in cycle: "Use power while you lose power".   For the reel-out cycle the slogan might be "Lose power and position, to make at least some power".  A rotor doesn;t need to lose power anytime, does not sacrifice its positioning to make power, and does not move downwind, giving up significant power, just to make power, and requires no "recovery cycle". I don't think there is anyone serious in this field, really.  People SAY they are pursuing AWE, but I don't see anyone really interested in getting it to work as an economical solution.  Hard to believe when there are so many simple and promising ways to do AWE, that nobody bothers to even try.

Attachments :

For Makani or FlygenKite the turbine is perpendicular in apparent wind, and its drag must not exceed half wing drag, limiting its size. Another variant is gyrocopter-kite where rotor drag is limited due to its AoA (10 to 30°), allowing a higher size and probably a better ratio swept area/drag, and perhaps a better ratio power/ weight of both structure and rotor. The joined paper describes drag rotor as lower than structure drag. Another possible advantage is inertia of bigger rotor allowing a more regular power in spite of variations of power due to kite positions in window of flight. In this configuration the flight is slower (3 or 4 times wind speed instead 4 (for high wind speed) to 8 (for low wind speed) times for Makani) and swept area of rotors is bigger. The question is maneuverability in loop or eight figures. 

 

PierreB